Lecture Notes: Bitewing Technique in Dental Radiography

Objectives

• Define key terms associated with the bitewing technique.
• Describe the purpose and use of the bitewing image.
• Describe the appearance of opened and overlapped contact areas on a bitewing image.
• State the basic principles of the bitewing technique.
• List two ways a receptor can be stabilized in the bitewing technique and identify the recommended method.
• List the three receptor sizes for bitewing technique and identify the recommended size for adult patients.
• Describe correct and incorrect horizontal angulation.
• Describe the difference between positive and negative vertical angulation.

Types of Bitewing Radiographs

• Horizontal Bitewing: Used for younger, healthier patients to check for decay and cavities between teeth and bone levels.
• Vertical Bitewing: Used for patients with periodontitis to view bone levels more clearly.

Comparison with Periapical X-Rays

• Periapical X-Ray: Shows entire tooth from crown to root, not both maxillary and mandibular teeth in one image.
• Bitewing X-Ray: Shows crowns of both maxillary and mandibular teeth on one image.

Purpose of Bitewing Radiographs

• Detect interproximal dental caries (decay) early.
• Assess alveolar bone levels and check existing restorations.
• Taken annually or as needed, more frequently than full mouth series.

Bitewing Technique Details

• Horizontal Angulation: Adjusted by moving the PID side-to-side.
• Vertical Angulation: Usually set at +10 degrees.
• Open Contacts: Desired outcome, showing clear space between teeth.
• Overlap: Non-diagnostic, requires retake.

Equipment and Devices

• Bitewing Beam Alignment Device: Ensures correct positioning and alignment, often color-coded red.
• Bitewing Tabs: Paper tabs used when beam alignment devices cannot be used, less accurate.
• Receptor Sizes:
  • Size 0: For children with primary teeth, horizontal.
  • Size 1: For older children or adults with small mouths, horizontal or vertical.
  • Size 2: Standard for adults, can be horizontal or vertical.

Common Errors

• Cone Cut: Caused by incorrect alignment, resulting in a partially exposed image.
• Incorrect Angulation: Leads to distorted images.
• Overlap: Due to incorrect horizontal angulation.

Patient Preparation

• Position patient’s head so maxillary arch is parallel to the floor.
• Remove eyewear and intraoral objects.
• Use a specific sequence to avoid errors.

Special Considerations

• Edentulous Spaces: Use cotton roll for support when teeth are missing.
• Tori: Adjust sensor placement to avoid discomfort.

Best Practices

• Set control factors before placing receptor in the mouth.
• Use a confident technique to command respect.
• Avoid positioning the receptor over bone growth.

Summary

• Bitewing technique is essential for early detection of decay and checking bone levels.
• Correct angulation and alignment are critical to avoid diagnostic errors such as overlap and cone cuts.
• Practical skills in lab will enhance understanding of theoretical knowledge.